Clicker die press with means to prevent platen creep



Oct. 27, 1964 A. MUHLBACH 3,153,965

CLICKER DIE PRESS WITH MEANS 'ro PREVENT PLATEN CREEP Filed Jan. 9, 1963 4 Sheets-Sheet 2 Oct. 27, 1964 A. MUHLBACH 3,

CLICKER DIE PRESS WITH MEANS TO PREVENT PLATEN CREEP Filed Jan. 9, 1963 4 Sheets-Sheet 5 Oct. 27, 1964 A. MUHLBACH 3,153,965

CLICKER DIE PRESS WITH MEANS TO PREVENT PLATEN CREE? 4 Sheets-Sheet 4 Filed Jan. 9, 1963 United States Patent 3,153,965 CLICKER DIE PRESS WITH MEANS T0 PREVENT PLATEN CREE? Anton Miihlhach, Frankfurt am Main, Sossenheim, Germany, assignor to United Shoe Machinery Corporation, Flemington, NHL, a corporation of New .lersey Filed Ian. 9, 1963, Ser. No. 250,287 Claims priority, application Germany, Jan. 31, 1962 7 (Ziaims. (@l. 83-525) This invention relates to improvements in clicker die cutting presses and more particularly to improvements in clicker die presses operated by fluid pressure motor means.

The invention is illustrated as embodied in a clicker die press having a fixed Work support and a movable platen cooperating therewith as the movable presser member. However, the invention is not to be considered as limited other than as required by the appended claims.

In the commercial use of clicker presses, there is frequent need for the operator to adjust the rest position of the upper press member usually called a platen so that in this rest position, that is, the heightwise position of the platen prior to the initiation of a cutting stroke, the platen will, when swung over a die resting on a work piece, clear the die by a comfortable but not excessive amount. Usually this distanw is a small fraction of an inch. When there is a change from one set of dies to a set having a diiierent height or a change in the thickness of the work piece, a suitable adjustment of the reset position is necessary or desirable. For this purpose it is common to provide hydraulic clicking presses with means for varying the coupling between the drive means and the platen as, for example, by the provision of a threaded spindle which may be rotated by means of a hand wheel to raise and lower the platen. Since the platen and its supporting column are relatively heavy, this requires a considerable eflort on the part of the operator, particularly in raising the platen. Power means for operating the threaded coupling have been tried but these require a large number of extra parts without insuring accuracy of heightwise positioning.

Other known means for determining the rest position by electrohydraulic control are relatively inaccurate and those which rely on locking up the pressure fluid in the motor cylinder when the rest position has been attained are subject to platen creep by loss of fluid so that an operator will tend to set the rest position higher than he would otherwise prefer.

Accordingly, a primary object of the present invention is to provide simple, rugged, economical and reliable means for adjustably establishing an accurate and stable rest position of the platen.

To this end and in accordance with the primary feature of the invention there is provided a hydraulic die cutting press having a movable presser member operated by a fluid pressure motor, means for supplying fluid under pressure to a distribution and utilization system comprising said motor and a valve connected mechanically to the movable presser member for controlling the exhaust of the pressure fluid from said system whereby the valve is operated to exhaust fluid to the sump and relieve fluid pressure in the motor cylinder when the platen has at: tained its rest position.

3,l53,%5 Patented Get. 27, 1964 ice Another object of the invention is to attain simplicity and accuracy in such an organization by incorporating said valve in the fluid pressure motor.

Another object is to provide means for conveniently adjusting the valve to change the rest position.

Yet another object of the invention is to provide power operated means for facilitating adjustment of the valve for adjustment of the rest position.

To these ends and in accordance with other features of the invention, one of two cooperative valve elements is embodied in a movable motor member while means are provided for adjusting the other valve element by manual or by fluid pressure means preferably derived from the source of pressure fluid which supplies the hydraulic motor although it will be understood that, if desired, a separate source of pressure fluid may be employed.

Still another object of the invention is to provide in a press organization embodying the primary feature of the invention improved mechanical and electrical control arrangements which comprise switch and valve elements facilitated by and cooperating advantageously with means providing the aforesaid primary features.

Other features and advantages of the invention will best be understood from the following description taken together with the accompanying drawings in which:

FIG. 1 is a side elevation of apparatus embodying the present invention;

FIG. 2 is a partial section of the apparatus shown in FIG. 1 and showing the hydraulic motor and the electric and hydraulic controls of one embodiment of the invention;

FIG. 3 is a partial section of valve means shown in FIG. 2 with its valve spool in a different position;

FIG. 4 is a view similar to FIG. 2 showing the hydraulic motor and hydraulic controls of a second embodiment of the invention;

FIG. 5 is a view similar to FIG. 2 showing the hydraulic motor and electric and hydraulic controls of a third embodiment of the invention; and

FIG. 6 is a partial section of valve means shown in FIG. 5 with the valve parts in different positions.

Referring to FIGS. 1 and 2, the illustrative cutting press comprises a frame F provided in the conventional manner with a work support S and a platen l secured to the upper end of a vertical column 2 and swingable in a horizontal plane. In use, a Work piece W of sheet material is placed on the work support and a die D which can be shifted about as desired on the work piece is pressed through the sheet material by the platen for dieing out parts.

In the lower part of the machine frame F, there is provided hydraulic drive means 3 for actuating the platen l. The hydraulic drive means 3 comprises a cylinder 4 and a piston 5, an axial extension 6, of which passes through one end of the cylinder and is fixedly connected by means of screws 7 to the lower end of the column 2. The piston 5, the column 2 and the platen 1 constitute the movable operating members of the clicking machine. The upper and lower chambers of the cylinder 4 on either side of the piston are connected, respectively, by pipes 8 and 9 to a solenoid valve itl. A pipe 11 leading from a pressure fluid sump carries fluid to a pump 12 and thence under pressure to a port 12' in the valve body, the valve operating as hereinafter described in greater detail to direct fluid under pressure through the pipe 3 into the upper chamber for the operating stroke or through the pipe 9 to the lower chamber for the re turn stroke of the platen 1.

The lower part of the cylinder 4 is closed by a cover 13 maintained liquid tight by means of an 0 ring 14. The cover is held in this position by several lugs 15 which are supported in a groove in the interior wall of the cylinder 4, the lugs being attached to the cover 13 by screws 16.

The cover 13 has an axial elongation in the form of a sleeve 17 provided with internal threads 1%. In the piston extension 6 there is an axial passage 19 which freely receives the sleeve 17 of the cover 13, this arrangement permitting space saving construction which facilitates the provision of bearings for the column 2. The diameter of the axial passage 1) undergoes an abrupt transition at the outer end of the piston extension 6, to a relatively narrow passage portion 29 forming at the transition a shoulder with a surface providing a valve seat means within the main portion of the axial passage. A transverse bore 21 connects the passage portion 2% with the pressure fluid sump. Into the threads 18 of the sleeve 17 there is threaded a member 22 which is pinned at 24 to a control rod 23 extending upwardly through the axial passage, the column 2 and the platen 1. 1n the illustrative embodiment, the upper end of the control rod 23 carries a hand wheel 25 by means of which the member 22 may be adjusted heightwise by rotation thereof. If desired, by means of additional connecting means, for example, a pair of bevel gears, there could be provided means for rotating the control rod from the forepart of the platen. A compression spring 2-6 on the control rod 23 supports a valve closure element comprising a sleeve 27 in a position determined by a ring abutment member 28 fastened on the control rod 23.

As shown in FIG. 2, an opening 29 is formed between the upper surface of the sleeve 27 and the surface 39. The size of the opening is determined by the weight of the movable clicker members and the flow rate of the pressure fluid flowing through the opening 29. In this manner, assuming a constant weight and flow rate, the position of the sleeve 2'7 determines the heightwise rest position of the platen 1. Thus the sleeve 2'7 together with the piston 5 formed with its axial passage and valve seat means constitutes an adjustable regulating valve generally identified by the reference numeral 31 and serving hydraulically to determine the rest position of the platen 1. If the platen 1 falls below its predetermined rest position, the sleeve 27 of this embodiment engages the surface 30, interrupting the exhaust of the pressure fluid and causing the platen to be raised. If desired, the closure element may be in the form of a ball which abuts only the edge of the portion 29, rather than a sleeve.

As shown in FIGS. 2 and 3, the solenoid valve 1h comprises a housing 35 rOII116d with a central chamber 4d and with an annular groove above the port 12'. in the housing 35, a valve spool 35 is supported by a spring 37 resting on a fixed ring 33. The valve spool as has a longitudinal bore 39 and a transverse bore 4i; for the flow of the pressure fluid to the sump. Above the valve spool 36 there is provided a pusher member 41 which is in engagement with an armature 42 of a solenoid 43. The solenoid 43 is fastened to the pump 12. and valve housing 35 by means of screws 44.

The initiation of the clicking operation is effected in known manner by energizing the solenoid for example, by means of a handle H (FIG. 1) which is arranged on the end of the platen 1 and also serves for swinging the platen 1 about the axis of the supporting column 2. T he operation of the handle by the operator serves to actuate a microswitch (not shown) which in known manner closes the circuit for energizing the solenoid 43. Thereupon the armature 42, acting through the pusher member 41, pushes the valve spool 36 against the force of the spring 37 downwardly into the position shown in FIG. 3, so that the pressure fluid flows from the pump 12 through the port 12, a chamber as and the pipe 8 into the chamber of the cylinder 4 located above the piston 5.

Accordingly, the movable parts, that is, the platen 1 the column 2 and the piston 5 of the clicking machine are moved downwardly to perform an operating stroke. During this movement the opening 29 is closed by reason of the engagement of the sleeve 27 with the surface 30. During the clicking stroke the sleeve 27 is moved downwardly against the force of the compression spring 26 by the surface 3%, whereas the position of the control rod 23 together with the abutment member 28 is not varied at all. The pressure fluid in the cylinder 4 below the piston 5 flows through the pipe 9 into an interior space 47 of the valve spool 36 and from there through the bores 49 and 39 into the pressure fluid sump.

The reversal of the platen 1 after its clicking stroke can be initiated electrically either by means of a microswitch or by the contact of the die used with an electrically conductive work support in accordance with the teaching of US. Patent No. 2,788,070 Seabury 11 et al., and has no influence upon the regulating valve 31 for determining the position of the platen 1.

The mode of operation of the regulating valve 31 during return of the platen 1 to its rest position after the operating stroke will now be described.

Upon the deenergization of the solenoid 43 after the conclusion of the clicking stroke the valve spool as is returned to its initial position under the action of the spring 37 so that the reversal of the platen 1 is effected by the hydraulic means. The pressure fluid flows from the port 12 through the chamber 45 into the pipe 9 and from there into the lower chamber of the cylinder 4. The opening 29 is closed by engagement of the sleeve 27 with the surface 3%, so that no pressure fluid can escape through the passage portion 21). Since the piston 5 is constructed as a differential piston having upper and lower surfaces and 2195, respectively, of different sizes, the piston 5 and the platen 1 are moved upwardly under the pressure exerted by the pressure fluid on the larger surface 205 of the piston 5, the pressure fluid contained in the upper chamber of the cylinder 4 flowing through the pipe 8 into the chamber of the valve housing 35 and thence through the pipe 9 to the lower chamber. During the entire return movement of the platen 1 the orifice of the passage portion 2d remains closed by the sleeve 27 and is open only when the sleeve 27 abuts the fixed abutment member 28 held by the control rod 23. The pressure fluid fed by the pump accordingly raises the platen 1, the column 2 and the piston 5 until the opening 29 is large enough to permit the pressure fluid to flow through the passage portion 269 and the bore 21 into the sump at the delivery rate. Tms equalization occurs completely automatically, the platen 1 remaining in its rest position. As soon as the opening 29 and thereby the flow diameter is narrowed or enlarged by external action upon the sleeve 27, the platen 1 immediately follows this change and is moved upwardly or downwardly until the normal flow diameter of the opening 21 has been restored.

Another substantial advantage of supporting the platen 1 in its rest position by continuously circulating pressure fluid is the fact that the upward movement of the platen 1 is terminated neither by fixed abutments nor by sudden interruption of the supply of pressure fluid which otherwise might result in sudden shocks and vibrations within the machine body. Rather the platen 1 is moved very smoothly into its final position by the uninterrupted flow of the pressure fluid into and finally through the cylinder in spite of the high speed of the return move ment.

In the clicking machine shown in FIG. 2, the reversal is elfected electrically by means of a limit switch 57 which, in known manner, is adjustable to vary the time of the termination of the clicking stroke so that varying depth of the penetration of the work support can be obtained for the purpose of completely cutting the work piece. The simple arrangement or" the limit switch 57 on a lever and a link and the space saving construction within the supporting column 2 out of which an adjusting rod extends to the front part of the platen 1, is important in the present embodiment. A bell crank lever 56, having a fixed pivot 51, is located Within the supporting column 2. Below the bell crank lever 50 there is provided a link 52 which is pivotally mounted at 53. The bell crank lever 50 and the link 52 are joined by pivot pins 54 and 55, having the same spacing as the pivots 51 and 53, to a triangular member 56. At the lower part of the triangular member 56 the limit switch is attached by screws 58. An adjusting rod 59 has a threaded end 59 which engages internal threads provided in the column 2. The other end of the adjusting rod 59 carries an adjusting knob 60. A short arm 50 of the bell crank lever 59 abuts the threaded end of the adjusting rod 59 and is held in this position by a tension spring 61. By rotating the adjusting rod 59, the parallel link mounting of the bell crank lever 50 and the link 52 acts to lower or raise the limit switch 57, maintaining it however, in a horizontal position. The control rod 23 for varying the position of the platen 1 relative to the work support remains at rest during the movement of the platen 1 and so does a ring 62 provided on the control rod 23. After the initiation of the machine stroke by the solenoid 43, the column 2 and the limit switch moves downward until a button 63 of the limit switch 57 engages the ring 62 so that the limit switch 57 is operated to deenergize the solenoid 43. Thereupon, the valve spool 36 is returned to its (upper) initial position whereupon the clicking stroke, as mentioned above, is terminated. The return portion of the stroke of the platen 1 is simultaneously commenced and continues until after the sleeve 27 engages the abutment member 28 and is held thereby and until the normal size of the Opening 29 for the flow of the pressure fluid supporting the platen 1 has been restored.

With each variation of the heightwise position of the platen 1 by means of the handle 25 for the purpose of, for example, using dies of different heights, the clicking stroke X, once adjusted by means of the adjusting knob 68, remains unchanged throughout the entire range of adjustment of the control rod, since the limit switch arrangement is coupled to the movable parts of the clicking machine and participates in any such adjustment.

Where it is desired to effect stroke reversal in the contact mode by contact between the die and the work support in accordance with the teaching of the aforementioned patent, the position of the limit switch 57 and thus the distance X may be enlarged by the adjusting knob beyond the maximum clicking stroke length so that no engagement of the button 63 with the ring 62 is possible during the clicking stroke. The particular advantage of the invention consists in that the clicking machine may be switched over without difficulty from contact mode to stroke limit mode of reversal of the platen 1 in which reversal is effected by means of limit switches for the purpose of enabling the clicking machine to operate upon conductive work pieces.

The embodiment of the clicking machine shown in FIG. 4 utilizes an auxiliary control for varying the rest position of the platen in combination with contact mode reversal of the above-mentioned type in which the clicking operation is terminated by the engagement of the die with an electrically conductive work support. The stroke adjustment of the platen 1 is effected by employing the pres sure fluid for the hydraulic drive means 3. The sleeve 17 of the cover 13' has a smooth cylindrical bore 65 instead of the thread 18 of the FIG. 2 embodiment. A

piston 66 is located within the bore 65 and is rendered liquid tight by O-rings 67. A control rod 68 is shorter than the control rod 23 of the FIG. 2 embodiment and supports at its upper end a closure sleeve 27' formed with a guiding flange 70. A ring member 28 serves as abutment and as the limit for the movement of the closure sleeve 27' on the control rod 68. A spring 26' maintains the sleeve 2'7 in its upper position while the flange 70 slides in an axial passage 19' of a piston extension 6 and thus supports the upper end of the control rod 68. The flange 70 is also provided with several circumferential passageways 71 to permit the pressure fluid to flow there through. All other members of the regulating valve according to the invention, such as a surface 30, a passage portion 28 and a transverse bore 21, have the same function with respect to the exhaust of the pressure fluid, as has been described in connection with the embodiment of FIGS. 2 and 3 and the same applies for the hydraulic drive means 3'.

The heightwise adjustment of the piston 66 and thus the variation of the position of the platen I with respect to the Work support is effected by an externally located control valve 72. The control valve 72 has a longitudinal bore 81 into which fit at a right angle two threaded spindles 73 and 74, the points of which are shaped as cones 73 and 74. The bore 81 is connected to the pressure fluid in the lower chamber 88 of the cylinder 4 by a pipe 78 and to a cylinder space 82 below the piston 66 by a pipe 79. Each of the threaded spindles 73 and 74 carries a knob 76 and 77. A pipe 83 leads from the bore 81 to the pressure fluid sump. The pipes 78 and 83 in the position shown on FIG. 4 are normally closed while the machine is at rest (as well as when a clicking stroke is performed) by the cones 73 and 74' so that the piston 66 remains at rest, because the pressure fluid below the piston 66 is trapped in the chamber 82 since it cannot flow past the cones 73' and 74' while the fluid above the piston 66 in a space is pressurized by its communication with the chamber 80. But if the cone 73' of the threaded spindle 73 is moved away from the entrance of the pipe 78 by the rotation of the knob '76, high pressure fluid is admitted to the bore 81 from the pipe 78 and thence to the pipe 79 and from there to the cylinder space 82 below the piston 66. Although the pressure of the pressure fluid above and below the piston 66 is equal, the lower surface 66' of the piston 66 is larger than its upper surface 66" and hence a greater force is exerted on the surface 66' than upon the surface 66" so that the piston 66 is moved upwardly until the pipe 78 is again completely closed by the tightening of the threaded spindle 73.

If instead the spindle 74 is rotated to open the pipe 8 to the sump, the piston 66 is moved downward as. long as the pipe 83 remains open.

If it is desired to employ a means other than the pressure fluid within the machine for operating the piston 66, the pipe 78 is disconnected from the cylinder space 80 and connected in known manner to an additional pressure fluid system.

In the embodiment of FIGS. 5 and 6 the solenoid valve 10 with the valve spool 36 and the pipe 9 of FIGS. 2, 3 and 4 are omitted, but the regulating valve 31 of FIG. 4 is employed in conjunction with the pressure fluid for the hydraulic drive means in order to accomplish the variation of the rest position of the platen 1 in the hereinbefore described manner. This variation is effected by the means used in the FIG. 4 embodiment.

The valve member for reversing the movement of the platen 1 is formed as a sleeve 98 according to FIGS. 5 and 6 and is concentrically arranged with a piston eX- tension 6 of an operating piston 5 of the hydraulic drive means 3". Annular grooves 91 and 91 are provided in the sleeve equidistant from its top and bottom ends. Each of the grooves 91 and 91 communicates with the interior of the sleeve 90 through several radially extending bores 92 and 92'. The sleeve 98 is held in its upward position in engagement with a surface 30" of the extension 6 by a compression spring 93 interposed between the bottom face 94 of the sleeve 90 and a ring member 95. The piston extension 6" also has transverse bores 96 connecting with bores 97 which terminate in an annular channel 953. Another annular channel 99 of the piston extension 6 is connected to the sump through a longitudinal bore 1% and a transverse bore 101. A supply line 102 is connected to an upper chamber 103 of the cylinder 4".

The position of the sleeve a piston 1%, operating piston 2.05 and sleeve 27", shown in FIG. 5, corresponds to the rest position of FIG. 2. The movable parts, the platen 1 and its supporting column 2 are supported by the pressure fluid flowing through the opening 2%.

The flow of the pressure fluid when the clicking machine is at rest is as follows: the pressure fluid supplied by a the supply line 102 into the cylinder space 1% and pump, which is not illustrated in FIG. 5, flows through through the bores 96 and 97 into the annular channel Q8. From there the pressure fluid flows into the groove 91', the bores 92' into an interior space 164 of the sleeve 91 for supporting the movable parts 1 and 2 past the sleeve 27" and through the bores 1% and 101 back into the sump. At the same time, the pressure fluid is admitted to a lower chamber 108 below the operating piston 5" and to a space 107 above the piston 1% which communicates with the space 104.

A solenoid tea for operating the sleeve as and thus for initiating the clicking operation is fixedly arranged in the upper part of the supporting column 2" and screwed at 111 to a cover 110 thereof. The armature 112 of the solenoid 109 acts upon a rod 113 and a pin 114', which in turn acts upon the sleeve 9%. The rod 113 and the pin 114 are held by a spring 115 in the upper position shown in FIG. 5. In order to initiate the clicking operation, a handle H (FIG. 1) on the front part of the platen 1 is operated to actuate a switch whereby the solenoid 153% is energized. Thus the armature 112 is operated to move the sleeve 90 into the position shown in 6 against the force of the springs 115 and $3. The annular groove 91 is thereby moved out of communication with the channel 93 so that the pressure fluid in the chamber 162? can become effective to move downwardly the operating piston 5" together with the supporting column 2. and the platen 1. Because of the downward movement of the sleeve 90, the groove 91 has been simultaneously connected with the annular channel Q9 so that the pressure fluid located below the operating piston 55 can flow through the radial bores 92 and the bores 1% and 191 to the sump. The opening 2-9" is then closed by the sleeve 27" which has engaged the surface 3%". The platen 1 continues to move downwardly to perform the clicking operation and is reversed at the moment in which the sleeve hit is returned to its initial position, closing off the channel 9% to the sump and opening the channels between the upper and lower chambers of the cylinder 4". The platen 1 then moves upwardly until the opening 29" has been restored, through which the pressure fluid can be exhausted.

The deenergization of the solenoid 169 is effected and thus the return of the sleeve 90 is efiected in the present embodiment by the engagement of the die with an electrically conductive work support. However, the return of the sleeve 9% to its initial position can also be accor plished mechanically or electrically.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a clicker die cutting press for cutting out parts from sheet material work pieces, in combination, a frame, a work support carried by the frame, a presser member mounted on the frame for swinging over the work sport and for movement toward and away from the work support for pressing dies through work pieces carried on the work support, a fluid pressure operated motor comprising a cylinder mounted on the frame and a piston dividing the space within the cylinder into upper and lower chambers, the piston being formed with an orifice therethrough and connected through the upper end of the cylinder to the presser member for effecting movement thereof in pressing dies through work pieces on the work support, a surface of the piston defining a valve seat about said orifice, means for supplying fluid under pressure selectively to the upper and lower chambers of said motor for effecting movements of the presser member and a regulating valve for controlling the exhaust of pressure fluid from the lower chamber of the hydraulic motor for maintaining the presser member at a predetermined upper position between strokes thereof, said valve comprising a control rod disposed for free longitudinal movement through said orifice and the upper end of the cylinder, means for supporting said rod in longitudinally adjustable disposition, a valve closure element slidably carried by said rod below the valve seat and adapted for cooperation therewith to close the orifice between the valve seat and the rod, means for yieldably urging the element upwardly on the rod for holding the element in sealing relation with the valve seat when the piston is below a predetermined position, and an abutment on the rod for limiting the upward movement of the element thereon, whereby upon upward movement of the piston beyond said predetermined position said valve seat and closure element are separated to permit escape of pressure fluid from the lower chamber of the motor through said orifice.

2. Apparatus as in claim 1 wherein the control rod is supported by a threaded connection at the lower end of the cylinder and is provided with manual means for effecting rotation thereof for adjusting its longitudinal disposition.

3. Apparatus as in claim 1 and additionally comprising a switch arranged for actuation by relative movement of the movable presser member and the control rod at a variable predetermined relative position thereof.

4. In a clicker die cutting press for cutting out parts from sheet material work pieces, in combination, a frame, a pair of cooperative upper and lower presser members mounted on the frame, the upper member being mounted for heightwise movement toward and away from the other presser member, a fluid pressure operated motor mounted on the frame and connected to the upper presser member for effecting movement thereof, said motor comprising a cylinder having at one end closure means comprising a sleeve formed with an axial cylindrical bore, said motor also comprising a piston slidably received in the cylinder and connected to the upper presser member, said piston having a piston extension passing through the other end of the cylinder and formed with an axial passage having an abruptly reduced diameter defining a valve seat surface, a piston member slidable within the cylindrical bore of the closure means, a control rod extending axially of the cylinder and having one end connected to the piston member, an abutment member mounted on the control rod, valve closure means slidable on the control rod and adapted to engage the seat surface in passage sealing relation, means resiliently urging the closure element toward the abutment member, means for supplying fluid under pressure to the motor for effecting movement of the upper presser memher, and means for selectively applying fluid pressure to the sides of the piston member for adjusting the position of the control rod within the cylinder.

5. Apparatus as in claim 4 wherein one side of the piston member has a larger effective area than the other, the space within the cylindrical bore on the smaller side of the piston communicating with the chamber of the motor pro vided with fluid under pressure in providing lifting force on the presser member, and additionally comprising valve and conduit means for selectively connecting the space on the other side of the piston member to said chamber or to exhaust.

6. Apparatus as in claim 4 and additionally comprising a sleeve slidable in the axial passage between a first and a second position, said sleeve and said piston being provided with cooperative passage means for controlling the admission of pressure fluid to the motor and the exhaust of the fluid therefrom whereby the motor is caused to move the presser member in one direction in the first position of the sleeve and in the other direction in the second position.

7. Apparatus as in claim 6 wherein the fluid under pressure is admitted to the cylinder only to the member at the side of the piston which is reduced in elfective area by the piston extension and wherein the sleeve cooperates with the piston in said first position to admit fluid from said chamber to the other chamber on the other side of the piston and in the second position to seal first said chamber while connecting the other chamber to exhaust.

Ernst et a1 Mar. 4, 1941 Stratton et a1 J an. 7, 1958 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION V Patent No. 3,153,965 1 I October 27, 1964 Anton Muhlbach It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below v Column 1, line 30, for "reset" read rest column 4,

line 50, for "open" read opened column 5, line 35; for "moves" read move column 7, lines 17 andl8, for "the supply line 102 into the cylinder space lQYS and pump, which is I not illustrated in FIG. 5, flows through" read pump, which is not illustrated in FIG. 5, flows through the supply line 102 into the cylinder space 105 and. column 9,- linelO, for.

"member" read chamber Signed and sealed this 10th dayof'August 1965.

(SEAL) LttCSt:

ERNEST w. SWIDER Y EDWARD J. BRENNER i .ttesting Officer Commissioner of Patents 

1. IN A CLICKER DIE CUTTING PRESS FOR CUTTING OUT PARTS FROM SHEET MATERIAL WORK PIECES, IN COMBINATION, A FRAME, A WORK SUPPORT CARRIED BY THE FRAME, A PRESSER MEMBER MOUNTED ON THE FRAME FOR SWINGING OVER THE WORK SUPPORT AND FOR MOVEMENT TOWARD AND AWAY FROM THE WORK SUPPORT FOR PRESSING DIES THROUGH WORK PIECES CARRIED ON THE WORK SUPPORT, A FLUID PRESSURE OPERATED MOTOR COMPRISING A CYLINDER MOUNTED ON THE FRAME AND A PISTON DIVIDING THE SPACE WITHIN THE CYLINDER INTO UPPER AND LOWER CHAMBERS, THE PISTON BEING FORMED WITH AN ORIFICE THERETHROUGH AND CONNECTED THROUGH THE UPPER END OF THE CYLINDER TO THE PRESSER MEMBER FOR EFFECTING MOVEMENT THEREOF IN PRESSING DIES THROUGH WORK PIECES ON THE WORK SUPPORT, A SURFACE OF THE PISTON DEFINING A VALVE SEAT ABOUT SAID ORIFICE, MEANS FOR SUPPLYING FLUID UNDER PRESSURE SELECTIVELY TO THE UPPER AND LOWER CHAMBERS OF SAID MOTOR FOR EFFECTING MOVEMENTS OF THE PRESSER MEMBER AND A REGULATING VALVE FOR CONTROLLING THE EXHAUST OF PRESSURE FLUID FROM THE LOWER CHAMBER OF THE HYDRAULIC MOTOR FOR MAINTAINING THE PRESSER MEMBER AT A PREDETERMINED UPPER POSITION BETWEEN STROKES THEREOF, SAID VALVE COMPRISING A CONTROL ROD DISPOSED FOR FREE LONGITUDINAL MOVEMENT THROUGH SAID ORIFICE AND THE UPPER END OF THE CYLINDER, MEANS FOR SUPPORTING SAID ROD IN LONGITUDINALLY ADJUSTABLE DISPOSITION, A VALVE CLOSURE ELEMENT SLIDABLY CARRIED BY SAID ROD BELOW THE VALVE SEAT AND ADAPTED FOR COOPERATION THEREWITH TO CLOSE THE ORIFICE BETWEEN THE VALVE SEAT AND THE ROD, MEANS FOR YIELDABLY URGING THE ELEMENT UPWARDLY ON THE ROD FOR HOLDING THE ELEMENT IN SEALING RELATION WITH THE VALVE SEAT WHEN THE PISTON IS BELOW A PREDETERMINED POSITION, AND AN ABUTMENT ON THE ROD FOR LIMITING THE UPWARD MOVEMENT OF THE ELEMENT THEREON, WHEREBY UPON UPWARD MOVEMENT OF THE PISTON BEYOND SAID PREDETERMINED POSITION SAID VALVE SEAT ANDCLOSURE ELEMENT ARE SEPARATED TO PERMIT ESCAPE OF PRESSURE FLUID FROM THE LOWER CHAMBER OF THE MOTOR THROUGH SAID ORIFICE. 